With continuous development of electronic technologies, electronic devices such as mobile phones and tablet computers have become a common communication tool in people's daily life. Using a mobile phone as an example, a subscriber identity module (SIM) card is an important component in the mobile phone and is installed on a card holder inside the mobile phone. Contact sheets that are used to connect to a power cable, a ground cable and each signal cable are disposed on the SIM card. When the SIM card is installed on the card holder, these contact sheets are electrically connected to corresponding pins on the card holder, and are further connected to a modem of the mobile phone by using the card holder.
A normal power-off sequence for each contact sheet on the SIM card has each signal cable powered off before the power cable is powered off. However, in a process in which a user uses the mobile phone, the SIM card may be inserted or removed in a case in which the mobile phone is not turned off, or the SIM card may be detached from the card holder when the mobile phone drops unexpectedly, which easily causes the SIM card to be powered off without following the normal sequence, thereby causing the SIM card to be burned out. In addition, in a research and development process of the mobile phone, especially in a process of a drop test for the mobile phone, the SIM card may also be detached from the card holder, causing the SIM card to be burned out. Therefore, there exists a technical problem in the prior art that a SIM card is prone to be burned out when being detached from a card holder.